Nerves of UL

Question 1

Where do the nerves of UL arise from?

Answer 1

brachial plexus

• anterior rami of c5-c8
• anterior ramus of t1

Question 2

What is the brachial plexus divided into?

Answer 2

3 anterior divisions (superior, middle, inferior)
3 cords (lateral, medial, posterior)

Question 3

What comes out of the supraclavicular part of brachial plexus?

Answer 3

dorsal scapular nerve - innervates rhomboids, levator scapulae

suprascapular nerve - supraspinatus, infraspinatus

Question 4

What is the supra scapular nerve susceptible to?

Answer 4

susceptible to being entrapped with supra scapular foramen: beneath ligament bridging supra scapular notch which leads to - weakened initiation of abduction of shoulder joint

Question 5

What are the nerves from the anterior and posterior division?

Answer 5

anterior: (M-shaped) - flexor
musculocutaneous
median
ulnar

posterior: extensor
radial
axillary

Question 6

What are the nerves from the 3 cords? (medial, lateral, posterior)

Answer 6

medial: median, ulnar
lateral: musculocutaneous, median
posterior: axillary, radial

Question 7

What does the musculocutaneous nerve supply?

Answer 7

from nerve fibres C5,6,7, it supplies the anterior compartment (flexor) of arm. it arises from lateral cord of brachial plexus and leave axilla via lateral wall between 2 heads of coracobrachialis.

coracobrachialis - biceps brachii - brachialis - elbow joint - lateral cutaneous nerve of forearm

Question 8

Injuries to musculocutaneous nerve

Answer 8

anterior dislocation to shoulder joint, fracture to humerus or a stab wound :

1) weakness of elbow flexion - paralysis of biceps brachii and brachialis
2) loss of sensation to skin on lateral forearm
3) biceps tendon jerk lost

Question 9

What does the median nerve supply?

Answer 9

consists of nerve fibres c6,7,8,t1. it arises from the medial and lateral cords of brachial plexus and innervates the anterior compartment of forearm (flexor).

pronator teres - flexor carpi radialis - palmaris longus - flexor digitorum superficialis - elbow joint - palmar cutaneous branch (goes through carpal tunnel) : also supplies medial half flexor digitorum profundus

anterior aspect - medial arm - cubital fossa - anterior forearm (between 2 heads of pronator teres)

Question 10

What is the major branch of the median nerve and what does it supply?

Answer 10

the major branch of the median nerve is the anterior interosseous nerve which supplies deep flexor muscles of forearm except medial part of flexor digitorum profundus (supplies lateral part of flexor digitorum profundus)

flexor pollicis longus - flexor digitorum profundus (lateral) - pronator quadratus - wrist